Slope Stability Assessment

Jane & Cameron Blake                                                                                      22178-001-Rev0
                                                                                                             26 May 2022

2.2    Topography
During the site walk-over, topographic features specific to the site were noted, and ground slopes were
recorded using a hand-held clinometer. As shown in Text Figure 4, the subject site is dominated by a ridge
which crests in the western part of the site. Multiple spurs emanate off the ridge crest, primarily dipping
towards the east, with drainage lines/gullies on either side of the spur crests. The main residence is
proposed to be cut into the crest of the ridge, with the proposed access driveway meandering up the eastern
flank. Generally, the existing residence, sheds and outbuildings were located near the crest of a south-
easterly dipping spur, emanating off the main ridgeline. Four dams were located on lower-lying areas along
the eastern boundary and to south of the property.
Cut and fill earthworks had been undertaken in the central part of the site presumably during construction of
the existing structures. Based on a visual appraisal it appeared that cut and fill earthworks in the order of
about 1 m depth/height had been undertaken. Unretained fill batters typically were battered at less than 20°.

Natural slopes across the central part of the site (i.e. proposed new shed, outbuildings and horse arena),
typically were less than 10°, reducing to <5° along the eastern boundary. Gradients across the proposed
new residence area generally varied from relatively level atop the ridge crest, up to about 10° immediately
down the flanks. Steeper gradients were recorded further down the ridge flanks and within drainage lines
generally ranging up to about 25°.




Approx. Proposed New Residence




                                                                  Approx. Proposed Sheds, Outbuildings and Horse Arena




Text Figure 4: Image showing ground surface contours (courtesy SCC MyMaps)

Text Figures 5 to 7 below and overleaf illustrates site conditions at the time of the assessment.




Text Figure 5: North-easterly view of the central part of the site and proposed development area




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